Lens ventilation in goggles structure



Oct. 6, 1953 W. L. CHRISTENSEN ETAL LENS VENTILATION IN GOGGLES STRUCTURE Filed June 8, 1949 I INVENTORJ Chri Ire/n Jen mliam M CheJfarE. CY'OJJ Patented Oct. 6, 1953 LENS VENTILATION IN GOGGLES STRUCTURE William K. Christensen, Newton Highlands, and Chester E. Cross, East Sandwich, Mass.

Application June a, 1949, Serial No. 97,864

4 Claims. (01. 2-14) (Granted under '1 The invention described herein, if patented, maybe manufactured and used by or for the 1 Government for governmental purposes without the payment to us of any royalty thereon.

This invention relates to improved gog lenses, and more particularly to the provision of anti-fogging or anti-frosting goggle lens for use in low ambient temperatures.

In the field of goggles-making, developments and improvements are constantly being made in both lens and frame structures. From actual testing under low ambient temperature conditions, however, it has been discovered that goggles heretofore available are subject to such fogging and frosting as to cause detrimental obstruction to vision. Particularly is this true under conditions of temperatures within the range of minus20 to minus 49 F. and lower. Generally, it may be stated that, in all the structures heretofore known, improper ventilation is primarily the cause of frost formation at low temperatures,-

Accordingly, it is an object of this invention to provide a new and improved goggles ventilating means for protectin the lens of a goggles from fogging and frosting.

It is another object of this invention to provide an improved goggles lens and goggles structure through which a constant flow of air is maintained against the inner surface of the lens to afford a rapid removal of any moisture tending to collect thereon.

It is a further object of this invention to provide a new and improved goggles having a lens incorporating inlet and outlet means thereon for inducing a flow of fresh ventilating air through the eye-cups of the goggles along theinner side of the lens which entrains air in the eye-cup cavities warmed by contact with the wearers face Fig. 2, a cross sectional view on line 2-2 of Fig. 1; and

Fig. 3 is a fragmentary perspective view of the improved lens structure.

Referring to the drawings, the goggles frame it comp-rises a conventional; rubber-type, integral flexible structure, having a resilient curved face-contacting part i I, a non-perforated web I2 and a beaded edge i3, which includes a lensholding groove [4.

Title 35, U. S. Code (1952) see. 266) The head l3 and groove M are interconnected by the web I2, and are adapted to aiford a flexible mounting within which a lens 55 of cellulose acetate, or other plastic or transparent material, is adapted to be fitted. The general structure of the goggles frame It, as heretofore indicated, is of a conventional character, and has securedthereto, by use of a rubber adhesive, or the like, a nose protector it, formed of suitable cloth or chamois material, which may have integral therewith a coating It for the facecontacting part II that is adhesively joined to the face contacting part II.

As illustrated in Fig. 1, the lens 15 has a plurality of uniformly spaced inlet ports I! adjacent its lower marginal edge portion l5. These ports may be on the order of %-inch square and are formed by a series of inverted U-shaped cuts in the lens on each side of the bridge portion thereof adjacent its lower edge which form tongues I8 that may be inclined backwardly along their lower edge (Fig. 3) to provide upwardly and rearwardly inclined fins or baffles on the ports ll.

Across the upper margin of the lens [5 there is provided a'series of equally-spaced rectangular outlet apertures or ports is in the lens 15 provided with chute-like baffles 20. These apertures or ports it are disposed in substantially uniformly spaced relation in the upper margin of lens 15 and in substantially opposed relation to the parts H along the lower margin of the lens, The bafiles 26 are formed of transparent cellulose acetate, or other material hav- "ing-thesa'me index of refraction as the lens l5, and comprise a generallyrectangular front wall .21 and triangular side walls 22 the edges 22' of which are secured to the surface of the lens 15 along the vertical edge of the ports is by a suitable transparent adhesive in the nature of cellulose acetate or the like preferably of equivalent transparency.

From, the above description of the invention,

it will be understood that a flow of fresh ventilating air over the inner surface of lens I5 is maintained by virtue of the fact that the inclination of the vanes or baflles 18 on the lower or inlet ports 17 induces a flow of fresh air into the space behind the lens and upwardly along the inner side of the lens, while the inclination of the baffles 28 on the outlet ports 59 induces a .with the face of the-wearer. Part of this latter component of the discharging air stream is entrained in the outwardly flowing ventilating air and part of it consists of air passing outwardly by convection. It will be observed that the lower edges of outlet ports and upper edges of inlet ports i! preferably are sufficiently distant from each other so that they are beyond the normal line or range of vision of the wearer of the goggles and thus do not interfere with visibility.

As heretofore described, the lens I5 is adapted to be positioned into the groove H by reason of the assemblys flexibility. As is conventional, the lens I5 is further secured within the frame ID by means of head straps 23, threaded through loops If! on frame I and provided with suitable ends adapted to be fitted within the T-cut slots 24 and anchored in a conventional manner. The lens I is likewise provided with suitable apertures or eyelets through which snap fasteners 5.5 are adapted to be secured. In certain goggles structure the head straps 23, or other holding means may be secured to the goggles frame i in a conventional manner, if desired.

With the assembly arranged in the manner described and illustrated, and the surface portions of the air guideways l8 and 2| positioned at an angle of approximately 70 to 85 with respect to the normal or axis of lens I5, there is provided, under conditions of low ambient temperatures, a definite flow of air over substantially the entire interior visual surface area of lens l5. This constant flow affords means for ready removal of moisture which tends to collect on the lens within the area of the eye cup and also rapidly removes any condensation which may occur due to sudden change of temperature conditions. Further, under conditions of excessively low temperatures, -40 F. and lower, and strong winds, this type of goggles produces in some instances an unfavorably chilling effect about the eyes, and it is, therefore, to be understood that it is more suitable for use under conditions where low temperatures exist without excessive wind velocities.

As an illustration of the improvements herein provided for protecting lens from fogging and frosting, the results in preventative time relationships between this structure and standard conventional lenses under conditions of tests for periods of one hour are indicated in the following table.

Comparison of standard and improved goggles [Exposure temperatureMinus F. Values in minutes of frost freedom] Subject Standard Improved Mean 4. 3 60 exception that "6 was replaced by '10," at a temperature of minus 40 F., under similar conditions of exposure, gave the following results.

Comparison of standard and improved goggles [Exposure temperature-minus 40 F. Values in minutes of frost freedom] subjects 2, 5 and 8 are somewhat less for the improved goggles under this temperature condition, reducing the mean time for frost-freedom, which is still considerably in excess of the mean frosting time of the standard goggle.

From the above description it will be apparent that, with the improvement provided herein, a lens structure for goggles or the like may be made from suitable plastic or other lens materials of a character known to the trade and with or without polarization and suitable coloring agents, if desired. Further, that the air flow guide means may be formed integral with the lens or added in other suitable manner to eliminate fogging and frosting of the lenses, and it will be apparent that such adaptations, alterations and modifications may be made as would fall within the Scope of the appended claims.

We claim:

1. An anti-fogging and anti-frosting goggles comprising a flexible frame including a flexible part to contact the face of a wearer in substantially sea-led relation thereto, transparent lens forming means in the forward side of said frame cooperating therewith to define a substantially sealed chamber behind the lens when the goggles are being worn, ventilating air inlet and outlet ports in said lens forming means respectively along the bottom and to margins thereof, and baffles at said ports for directing a flow of ventilating air upwardly along the inner side of the lens forming means from the lower margin thereof to the upper, said baffies being formed of a transparent material having the same index of refraction as the material of the lens forming means.

2. An anti-fogging and anti-frosting goggles comprising a flexible frame including a flexible part to contact the face of a wearer in substantially sealed relation thereto, transparent lens forming means in the forward end of said frame cooperating therewith to define a substantially sealed chamber behind the lens when the goggles are worn, said lens forming means having a plurality of inlet and outlet ports in the bottom and top margins thereof respectively, inwardly and upwardly directed baiiles on the ports in the lower margin of said lens forming means, and outwardly and upwardly directed baflles on the ports in the upper margin of said lens forming means, said bafiles being constructed from material having the same index of refraction as the material of which the lens forming means is made and cooperating to effect a flow of fresh venti- V lating air through the space behind said lens forming means in close proximity to the inner side thereof.

3. An anti-fogging and anti-frosting goggles comprising a flexible frame including a flexible face contacting part to contact the face of a wearer in substantially sealed relation thereto, transparent flexible lens forming means in the forward end of said frame cooperating therewith to define a substantially sealed chamber behind the len when the goggles are worn, and means for producing a flow of fresh ventilating air through the space behind said lens forming means in close proximity to the inner side thereof including ports in the lower margin of the same formed by severing and bending portions of the lens forming means to form generally rectangular shaped upwardly and inwardly inclined fins on the inner side of said lens forming means, generally rectangular ports in the upper margin of said lens formin means, and upwardly and outwardly inclined baifles for the ports in the upper margin of said lens forming means, said balfles being of transparent material having the same index of refraction as the material of which the lens forming means is made.

4. A goggles lens comprising a sheet of transparent flexible material conforming in shape to the frame in which the lens is to be supported,

a plurality of inlet ports adjacent the lower margin of the lens formed by severing and bending portions of the lens to form generally rectangular shaped openings and correspondingly shaped upwardly and inwardly inclined bafiies on the inwardly facing side of said lens, generally rectangular outlet ports adjacent the upper margin of the lens, and upwardly and outwardly inclined chute shaped bafiles on the outwardly facing side of said lens for said outlets, said bailies being made of a transparent material having the same index of refraction as the material of which the lens is made.

WILLIAM R.- CHRISTENSEN.

CHESTER E. CROSS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 611,396 Sheldon Sept. 27, 1898 2,125,023 Hedin July 26, 1938 2,149,514 Fischer Mar. 7, 1939 2,387,849 Lehmberg et al Oct. 30, 1945 FOREIGN PATENTS Number Country Date 592,055 Great Britain Sept. 5, 1947 

